| Hyperkalemia alters endothelium-dependent relaxation through non-nitric oxide and noncyclooxygenase pathway: a mechanism for coronary dysfunction due to cardioplegia. | |
| | |
MedLine Citation:
|
PMID: 8633948 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
BACKGROUND: Reported results of hyperkalemia (cardioplegia or organ preservation solutions) on endothelial function are contradictory. The endothelium-dependent relaxation is related to three major mechanisms: cyclooxygenase, nitric oxide, and endothelium-derived hyperpolarizing factor (K+ channel related). The present study was designed to test the hypothesis that hyperkalemia may alter endothelial function through non-nitric oxide and noncyclooxygenase pathways. METHODS: Porcine coronary artery rings (5 to 10 in each group) were studied in organ chambers under physiologic pressure. After incubation with 20 or 50 mmol/L K+ for 1 hour, the response to substance P, an endothelium-dependent vasorelaxant peptide, in K+ (25 mmol/L)-induced contraction was studied in the presence of the cyclooxygenase inhibitor indomethacin (7 mumol/L), the nitric oxide biosynthesis inhibitor NG-nitro-L-arginine (L-NNA) (300 mumol/L), or the adenosine triphosphate-sensitive K(+)-channel blocker glybenclamide (3 mumol/L) in comparison with control arteries (69.8 +/- 4.6% of K+ contraction). RESULTS: Without exposure to hyperkalemia, indomethacin (with or without glybenclamide) did not alter but L-NNA significantly reduced the relaxation (39.7% +/- 3.7%, p < 0.001). After exposure to K+, the indomethacin- and L-NNA-resistant relaxation was further reduced (7.4% +/- 3.2% for 20 mmol/L K+, p < 0.0001; or 13.5% +/- 8.4% for 50 mmol/L K+, p < 0.05, compared with rings without exposure), whereas the indomethacin- and glybenclamide-resistant relaxation was not altered. Incubation with hyperkalemia (50 mmol/L) also significantly reduced the sensitivity (increased EC50) of the indomethacin- and L-NNA-resistant relaxation (-9.75 +/- 0.06 versus -9.33 +/- 0.04 log M, p < 0.01). CONCLUSIONS: Exposure to hyperkalemia reduces the indomethacin- and L-NNA-resistant, endothelium-dependent (endothelium-derived hyperpolarizing factor-related) relaxation. Our study may suggest a new mechanism of coronary dysfunction after exposure to hyperkalemia and open a new area for protection of coronary endothelium in cardiac surgery and for organ preservation in transplantation surgery. |
| | |
Authors:
|
G W He; C Q Yang |
Related Documents
:
|
21135808 - Contemporary issues in cardiac pacing. 8511028 - Effect of growth and maturation in a hypoxic environment on maximum coronary flow rates... 2590548 - Pharmacokinetics and central haemodynamic effects of doxorubicin and 4'epi-doxorubicin ... 7898068 - Effects of amlodipine on coronary hemodynamics and vascular responses to sympathetic st... 10215208 - Experimental application of microwave tissue coagulation to ventricular myocardium. 20451698 - Incidence of caffeine in serum of patients undergoing dipyridamole myocardial perfusion... |
Publication Detail:
|
Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: The Annals of thoracic surgery Volume: 61 ISSN: 0003-4975 ISO Abbreviation: Ann. Thorac. Surg. Publication Date: 1996 May |
Date Detail:
|
Created Date: 1996-07-02 Completed Date: 1996-07-02 Revised Date: 2010-03-24 |
Medline Journal Info:
|
Nlm Unique ID: 15030100R Medline TA: Ann Thorac Surg Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 1394-9 Citation Subset: AIM; IM |
Affiliation:
|
Department of Surgery, University of Hong Kong, Grantham Hospital, Aberdeen, Hong Kong. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Cardioplegic Solutions / pharmacology* Coronary Vessels / drug effects*, physiology Cyclooxygenase Inhibitors / pharmacology Endothelium, Vascular / drug effects*, metabolism, physiology Heart Arrest, Induced / adverse effects Heart Diseases / etiology, physiopathology Indomethacin / pharmacology Nitric Oxide / pharmacology, physiology* Swine |
| Chemical | |
Reg. No./Substance:
|
0/Cardioplegic Solutions; 0/Cyclooxygenase Inhibitors; 10102-43-9/Nitric Oxide; 53-86-1/Indomethacin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Surgical treatment of systemic atheroembolism from the thoracic aorta.
Next Document: Improved cardiac function after prolonged hypothermic ischemia with the Na+/H+ exchange inhibitor HO...